Sage MAS 90 and 200 have this option on the Inventory Main menu. It allows you to change either Prices or Standard Costs or both.
Select a Range of item numbers.
Change costs for a vendor
Change prices for an entire product line
Change prices for a price-code

Change prices by:
percent +/- of price change
percent +/- of cost
add or subtract $$ amount to price
add or subtract $$ amount to cost

Change Standard costs by:
percent change
added $$ amount
set to average cost
set to last cost

…but the update doesn’t affect GL, so if you are changing standard cost, you would need to correct the GL. The Inventory Valuation Report should be printed before and after the change and then used to make adjustments in the General Ledger.